Computations Of Critical Depth In Rivers With Flood Plains

Abstract

Critical flows may occur at more than one depth in rivers with flood plains. The possibility of multiple critical depths affects the water-surface profile calculations. Presently available algorithms determine only one of the critical depths which may lead to large errors. It is the purpose of this paper to present an analytical formulation of a compound-channel Froude number which correctly identifies the occurrence of points of minimum specific energy (Critical points) for flow in rivers with flood plains. A compound-channel Froude number (Eq.16) has been derived and has been shown to accurately predict the critical points in rivers with flood plains. The proposed compound-channel (froude number) can be used in conjunction with existing computer programs for water surface profile computations.

Keywords: (Surface Profile, Computations, Critical Depth, Rivers, Flood Plains, Froude Number, Specific Energy, Compound Channel)